Question

我是Android编程的新手，我制作的程序可以在按下按钮或单选按钮时更改textview的颜色。甚至我正在为this.Inow编写一个单独的Listner类。现在在activity和listner类和活动中它显示一个错误。我的活动类和Listner类已被附加在这里

主要活动错误显示在ColorSetter(b1.setOnClickListener(new ColorSetter(Color.RED, this));

的所有按钮和定量按钮中

public class MainActivity extends Activity {

    private View mColorRegion;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mColorRegion = findViewById(R.id.color_region);
    Button b1 = (Button)findViewById(R.id.button1);
    Button b2 = (Button)findViewById(R.id.button2);
    Button b3 = (Button)findViewById(R.id.button3);

            RadioButton r1 = (RadioButton)findViewById(R.id.radio_button1);
            RadioButton r2 = (RadioButton)findViewById(R.id.radio_button2);
            RadioButton r3 = (RadioButton)findViewById(R.id.radio_button3);

            b1.setOnClickListener(new ColorSetter(Color.RED, this));
            b2.setOnClickListener(new ColorSetter(Color.BLUE, this));
            b3.setOnClickListener(new ColorSetter(Color.YELLOW, this));
            r1.setOnClickListener(new ColorSetter(Color.RED, this));
            r2.setOnClickListener(new ColorSetter(Color.BLUE, this));
            r3.setOnClickListener(new ColorSetter(Color.YELLOW, this));

    }

    public void setRegionColor(int color) {
    mColorRegion.setBackgroundColor(color);
    }
}

Listner-plz解释了如何编写这个seprate listner

public class ColorSetter implements OnClickListener {

private int regionColor;
private Events1Example mainActivity;
public ColorSetter(int regionColor,Events1Example mainActivity) {
        this.regionColor = regionColor;
        this.mainActivity = mainActivity;
        }

@Override
public void onClick(View arg0) {
    // TODO Auto-generated method stub

    mainActivity.setRegionColor(regionColor);

}

}

Answer 1

我希望这是你所期望的。检查这种类型的代码。

  public class MainActivity extends Activity {

private View mColorRegion;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mColorRegion = findViewById(R.id.color_region);
    Button b1 = (Button)findViewById(R.id.button1);
    Button b2 = (Button)findViewById(R.id.button2);
    Button b3 = (Button)findViewById(R.id.button3);

    RadioButton r1 =
            (RadioButton)findViewById(R.id.radio_button1);
            RadioButton r2 =
            (RadioButton)findViewById(R.id.radio_button2);
            RadioButton r3 =
            (RadioButton)findViewById(R.id.radio_button3);

            b1.setOnClickListener(new ColorSetter(Color.RED, this));
            b2.setOnClickListener(new ColorSetter(Color.BLUE, this));
            b3.setOnClickListener(new ColorSetter(Color.YELLOW, this));
            r1.setOnClickListener(new ColorSetter(Color.RED, this));
            r2.setOnClickListener(new ColorSetter(Color.BLUE, this));
            r3.setOnClickListener(new ColorSetter(Color.YELLOW, this));

}
public void setRegionColor(int color) {
    mColorRegion.setBackgroundColor(color);
}
}


Button.OnClickListener btnOnClickListener=new Button.OnClickListener()
               {

                @Override
                public void onClick(View v) {




                    if(v==b1)
                    {

                       //b1 code goes here

                    }
                    else if(v==cb2)
                    {
                        //b2 code goes here
                    }


               };

Answer 2

更改此

private Events1Example mainActivity;
public ColorSetter(int regionColor,Events1Example mainActivity) {

到

private MainActivity mainActivity;
public ColorSetter(int regionColor,MainActivity mainActivity) {

Android错误 - 使用单独的Listener类

2 个答案: